We hypothesize that the hearts of HIV+ people with The Metabolic Syndrome use and oxidize fats and sugars inappropriately, and that this may impair the heart's ability to pump blood. We hypothesize that exercise training or pioglitazone (Actos) will improve fat and sugar metabolism in the hearts of HIV+ people with The Metabolic Syndrome. This study will advance our understanding of cardiovascular disease in HIV+ people, and will test the efficacy of exercise training and pioglitazone for improving insulin resistance, heart metabolism and heart function in this at risk population.

Radio-tracer (11C-glucose) and positron emission tomography quantification of myocardial glucose utilization rate. The rate at which glucose exits the blood, enters the muscle cells in the left ventricle, and is metabolized (ATP generation, glycolysis, glycogenolysis, or lactate production). Total glucose utilization rate in the left ventricle of the heart.

Radio-tracer (11C-glucose) and positron emission tomography quantification of myocardial glucose utilization rate per unit of plasma insulin. Total glucose utilization rate in the left ventricle of the heart expressed per unit of the circulating plasma insulin concentration.

Radio-tracer (11C-palmitate) and positron emission tomography quantification of myocardial fatty acid utilization rate. The rate at which palmitate exits the blood, enters the muscle cells in the left ventricle, and is metabolized (oxidation, re-esterification).

Echocardiographic quantification of (E/A) early to late diastolic filling velocity. Aria transfer blood to the ventricles in 2 steps:

blood collected in the atria falls into the ventricles when the atrioventricular valves opens. In the left heart, the velocity at which the blood moves during this initial action is called the early or "E" filling velocity.

residual blood in the atria, is emptied during diastole by atrial contraction. The velocity of the blood during atrial contraction is the "A" (for atrial) filling velocity. These are expressed as a ratio (E/A). If A exceeds E velocity (ratio <1.0) this is a clinical marker of diastolic dysfunction. This can occur when the left ventricular wall becomes so stiff as to impair proper filling, which can lead to diastolic heart failure.

We hypothesize that myocardial free fatty acid and glucose utilization and oxidation rates are dysregulated in HIV+ people with The Metabolic Syndrome in comparison to HIV+ people without The Metabolic Syndrome, and in comparison to HIV-seronegative people with and without The Metabolic Syndrome. We hypothesize that dysregulated myocardial fatty acid and glucose metabolism is associated with impaired heart function (diastolic dysfunction) in HIV+ people with The Metabolic Syndrome. We will use myocardial positron emission tomography, radioactive isotope tracers of palmitate and glucose, and echocardiography to evaluate myocardial metabolism and function. HIV+ people with The Metabolic Syndrome will receive 16wks of exercise training or pioglitazone (Actos), and we will evaluate their potential beneficial effects on myocardial metabolism and function.

Eligibility

Ages Eligible for Study:

28 Years to 50 Years (Adult)

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria: All participants both with and without metabolic syndrome:

Menstruating women must have a negative urine beta-HCG pregnancy test within 14 days prior to study. To control for potential metabolic effects of alterations in female hormones during the menstrual cycle, all menstruating women will be studied during the follicular phase (serum 17beta-estradiol <165 pg/mL).

Uncontrolled hypertension (>140/90 mmHg). Certain antihypertensive medications will be permitted (diuretics, ACE inhibitors) as long as the medication, dose, and blood pressure have been stable for at least 3 months.

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Please refer to this study by its ClinicalTrials.gov identifier: NCT00656851

Locations

United States, Missouri

Washington University School of Medicine

St. Louis, Missouri, United States, 63110

Sponsors and Collaborators

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)